Belt-tensioning device for threading machines and the like



April 17, 1928.

L. S. HALL BELT TENSIONING DEVICE FOR THREADING MACHINES AND THE LIKE Original Filed Febyls. 1524 2 Sheets-Sheet 1 TOR M444 lNVEN v I 15.5w: 5.

' RNEY April 17, 1928. 1,666,135

' L. S. HALL BELT TENSIONING DEVICE FOR THREADING MACHINES AND THE LIKE Original Filed Feb. 18. 1924 2 Sheets-Sheet 2 INVENTOR 4554/5 5 HALL Patented Apr. 17, 1928.

UNITED STATES LESLIE S. HALL, OF ERIE, PENNSYLVANIA, ASSIGNOR '10 WILLIAMS TOOL CORPORA- TION, OF ERIE, PENNSYLVANIA.

BELT-TENSIONING DEVICE FOR THREADING MACHINES AND THE LIKE.

.Original application filed February 18, 1924, Serial No. 693,604, and in Canada March 20, 1924. Divided and this application filed March 25, 1925. Serial No. 18,245.

My invention relates to machinery and primarily to that type known as pipe or bolt threading machines.

The primary object of my invention 1s to provide a machine of this character w th a new type of belt tensioning dev ce wlnch is simple in construction, effective 1n operation, and which is at all times under the constant control of the operator.

Another object is a provision of a swinging or pivoted platform or support for the motor which provides the source of power for driving the machine.

A still further object is to provide a novel and handy controlling device for the swinging motor.

Other objects and advantages in details of construction and operation will be apparent as the description proceeds, reference being had to the accompanying, drawings wherein like reference numerals indicate like parts.

This application is a division of my application Serial No. 693,604, filed February 18, 1924 for pipe threading machines.

In the drawing Figure 1 is a perspective view of a pipe threading machine equipped with my improved belt tensioning device.

Figure 2 is a detail view showing the operating device provided for the pivoted motor support.

1 Figure 3 is a side view of Figure 2 show ing more clearly the operating means and the pivoted motor support.

In Figure 1, I have illustrated generally a pipe threading machine such as that shown and described in the above entitled application of which this is a division. Although my invention is particularly adaptable to pipe threading machines of this character, it will be understood the same may be' used to advantage on many types of power driven machines where a belt forms the driving connection between the motor or other source of power and the machine mechanism.

The reference numeral 1 indicates gen erally my machine structure and comprises the base or frame which is preferably a casting. Front and rear chucks 2 and 3 are provided for rotating the pipe to be threaded. Located within the housing 4, is the driving mechanism (not shown) for operating the chucks. A head 5 of any improved form or type is slidably mounted by means of the carriage 6, on ways 7 extending through the machine and projecting therefrom. A bed 8 for receiving the used oil and cuttings is supported in any suitable manner directly beneath the head 5.

Mounted within the frame work or base 1 of the machine is an oil reservoir 9 out of which oil is drawn through a. pipe 10 by means of an oil pump 11 and forced through the pipe 12 to the cutting head 5, at which point it is controlled by the valve 13.

A shaft 14 mounted in bearings 15 extends laterally across the lower part of the bed or frame of the machine. Pivoted at one edge on this shaft 14 is a swinging frame or support- 16 to which is secured in any suitable manner the motor or other source of power 17. The rotor 18 of this motor is provided at its projecting end with a pulley 19. A driving belt 20 connects this pulley 19 with a pulley 21 rigidly mounted upon the driving shaft 22 of the machine. It will be noted that the weight of the motor 17 on the platform 16 when the latter is permitted to swing downwardly, draws the belt 20 taut between the pulley 19 and the pulley 21, thus providing sufficient frictional engagement to enable the belt to drive the driving shaft 22 and its connecting mechanism. I

Secured as by bolt 23 to the free end of the swinging platform 16, is a link 24. Adjustably engaging this link 24 is a second link 25. The pin and slot connection 26 and 27 forms a means of adjustment between these two links. The upper end of link is secured to one end of an arm 28, the other end of which is rigidly mounted on the end of a shaft 29 journaled in a bearing 30 formed in the base or frame of the machine. The outer or projecting end of the shaft 29 i squared as at 31 to receive a handle or crank 32.

It will be noted by reference to Figure 3, that when the handle 32 is in the raised position shown in full lines, the platforn'r 16 carrying the motor 17 is lowered to its full extent at which time the weight of these parts pulls the belt 20 tight, thus completing the driving connection between the motor and the driving shaft of the machine 22. It should be noted also that because of the pivoted connection of the platform 15 with the body of the machine 1, the tension on the belt 20 is yieldable so that in the event of gaging the gear driving mechanism con--v tained within the housing 4, the operator need only to grasp the handle or crank 32 turning 1t down to the dotted line position shown in Figure 3. In this position the eccentric arm 28 to which is secured the upper end of link 25 will be raised to a point just over the center of gravity or the dead center. As the shaft 29 is incapable of making a complete revolution in this direction because of the side wall of the frame work 1 lying in the path of the arm 28, it will be seen that the platform 16 carrying the motor 17 will be raised and secured whereby the tension is released completely on belt 20, thus allowin the motor to run freely but releasing its riving connection with the shaft 22.

The pin and slot connection 26 and 27 between links 24 and 25 permits adjustment of these two supporting) links to accommodate different lengths of elt and to compensate for stretching or shrinking of the belt material.

The motor may be of any suitable type but is preferably a small electric motor adapted to receive its energy from an ordinary light socket with which it may be connected by means of the switch plug 33 on one side of the base.

It is believed that the operation of the de vice is obvious from the foregoing description and the same will not be repeated here. It will be apparent to those. skilled in the art that the various elements described and shown in the accompanying drawings are of broad application and susceptible to a vasel - claims.

I claim:

1. In combination with a power machine including an upright frame, rotatable means mounted in upper portion of said frame, a platform pivoted in said frame below said rotatable means, a motor on said platform, a substantially vertical link in said frame secured at its lower end to and supporting the free side of said platform, a stub shaft in said frame carrying at one end an arm secured to the upper end of said link, driving means between said motor and said rotatable means, means on said stub shaft for rotating the same to raise and lower said link whereby the tension of said driving means is relieved, and means for locking said link in raised position.

2. In combination with a power machine, including an upright frame, rotatable means mounted in the upper portion of said frame, a platform pivoted in said frame below said rotatable means, a motor on said platform, a substantially vertical link in said frame secured at its lower end to and supporting the free side of said platform, a stub shaft in said frame carrying at one end an arm secured to the upper end of said link, driving means between said motor and said rotatable means, means on said stub shaft for rotating the same to raise and lower said link whereby the tension of said driving means is relieved, and means for locking said link in raised position, said means comprising a crank arm on said stub shaft for moving said link past the center of gravity, wherein the weight of said platform and motor locks said link in non-tensioning position.

LESLIE s. HALL. 

